Cardiac resynchronization therapy is not commonly used in the early postoperative period in patients undergoing cardiac surgery who have left ventricular (LV) dysfunction and a history of heart failure. We performed a prospective randomized clinical trial to compare atrial synchronous right ventricular (DDD RV) and biventricular (DDD BIV) pacing within 72 hours after cardiac surgery in patients with an EF ≤35 %, a QRS interval longer than 120 msec and who had LV dyssynchrony detected by real-time three-dimensional echocardiography (RT3DE). Epicardial pacing was provided by a modified Medtronic INSYNC III pacemaker. An LV epicardial pacing lead was implanted on the latest activated segment of the LV based on RT3DE. The study included 18 patients with ischemic heart disease, with or without valvular heart disease (14 men, 4 women, average age 71 years). Patients undergoing DDD BIV pacing had a statistically significant greater CO and CI (CO 6.7±1.8 l/min, CI 3.4±0.7 l/min/m(2)) than patients undergoing DDD RV pacing (CO 5.5±1.4 l/min, CI 2.8±0.7 l/min/m(2)), p<0.001. DDD BIV pacing in the early postoperative period after cardiac surgery corrects LV dyssynchrony and has better hemodynamic results than DDD RV pacing.